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World War II was the largest and most violent armed conflict in 
the history of mankind. However, the half century that now sepa- 
rates us from that conflict has exacted its toll on our collective 
knowledge. While World War II continues to absorb the interest of 
military scholars and historians, as well as its veterans, a generation 
of Americans has grown to maturity largely unaware of the politi- 
cal, social, and military implications of a war that, more than any 
other, united us as a people with a common purpose. 

Highly relevant today, World War II has much to teach us, not 
only about the profession of arms, but also about military pre- 
paredness, global strategy, and combined operations in the coali- 
tion war against fascism. During the next several years, the U.S. 
Army will participate in the nation's 50th anniversary commemo- 
ration of World War II. The commemoration will include the pub- 
lication of various materials to help educate Americans about that 
war. The works produced will provide great opportunities to learn 
about and renew pride in an Army that fought so magnificently in 
what has been called "the mighty endeavor." 

World War II was waged on land, on sea, and in the air over 
several diverse theaters of operation for approximately six years. 
The following essay is one of a series of campaign studies high- 
lighting those struggles that, with their accompanying suggestions 
for further reading, are designed to introduce you to one of the 
Army's significant military feats from that war. 

This brochure was prepared in the U.S. Army Center of Mili- 
tary History by Burton Wright III. I hope this absorbing account of 
that period will enhance your appreciation of American achieve- 
ments during World War II. 

General, United States Army 
Chief of Staff 

Eastern Mandates 

31 January- 14 June 1944 

The Japanese attack on Pearl Harbor in December 1941 was 
both a strategic and a political blunder. Japanese pilots not only 
failed to destroy the U.S. Navy's most lethal weapons, its aircraft 
carriers, but they also united the American people behind an Al- 
lied war effort that would lead to the defeat of military dictator- 
ships on two continents. 

The United States took a year after Pearl Harbor to arm and 
equip its forces before beginning sustained offensive operations in 
the Pacific. While formally supporting a plan to give priority to the 
war in Europe, the "Germany-first" policy, America nevertheless 
dispatched sufficient men and equipment to the Pacific in 1942 to 
halt the Japanese juggernaut. By the opening months of 1943 the 
U.S. Army and Marine Corps had fought and defeated the Impe- 
rial Japanese Army at Guadalcanal and, with the Australians, at 
Papua, New Guinea. At sea the U.S. Navy, although suffering 
heavy losses, had forced back the Imperial Japanese Navy in the 
Battles of the Coral Sea and Midway and in the waters around 
Guadalcanal, throwing it on the defensive. By mid-1943, U.S. po- 
litical and military planners were developing the plans that would 
carry Allied military might to the heart of the Japanese Empire. 

The primary American commanders in the Pacific developed 
different strategic concepts for pursuing the war against Japan. 
General Douglas MacArthur, commander in chief of the South- 
west Pacific Area, wanted to advance toward Japan along a New 
Guinea-Philippines axis. He reasoned that his concept would 
shield Australia from attack, make the best use of existing bases, 
and provide land-based support throughout most of the advance. 
MacArthur also hoped to isolate and bypass several well-fortified 
enemy bastions, as well as to fulfill his pledge to return to the 
Philippine Islands. Critics argued that his plan depended on a long 
and vulnerable supply line, was predictable and therefore subject 
to heavy resistance, and offered no decisive strategic results. 

Admiral Chester W. Nimitz, the commander in chief of the Pacific 
Ocean Area, wanted to thrust west from Hawaii, using sea power and 
carrier-based aircraft to seize isolated Japanese islands that could 
not be easily reinforced by the enemy. Once such footholds were se- 


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cure, he would carry the war directly to the Japanese homeland. His 
critics noted the danger of ignoring Australia as well as the difficulties 
of operating across extended ocean areas without land-based air- 
craft. Since both plans appeared feasible, Allied military and political 
leaders debated the merits of each for many months. 

The U.S. Joint Chiefs of Staff (JCS) unveiled their "Strategic 
Plan for the Defeat of Japan" during the Anglo-American Wash- 
ington Conference in May 1943. As a result of these deliberations, 
Nimitz was directed to conduct the primary campaign, following the 
shorter, more direct approach to Japan that he had advocated. 
MacArthur was ordered to conduct a secondary, or supporting, cam- 
paign that would both complement Nimitz 's effort and keep pressure 
on the Japanese across a wide expanse of territory. Although fre- 
quently modified during its existence, the JCS plan provided the 
blueprint for defeating the Japanese Empire in the Pacific. 

Strategic Setting 

One of the island groups targeted for invasion in the Joint Chiefs' 
plan was the Eastern Mandates, better known as the Marshall Is- 
lands. Under German control from the late 1890s through the end of 
World War I, the Marshalls had been assigned to the Japanese as 
mandates in accord with Article 22 of the League of Nations Charter. 

The Marshalls lie in two roughly parallel chains about 100 miles 
apart. The eastern, or "sunrise," chain contains the large atolls of 
Mille, Maloelap, and Wotje. The western, or "sunset," chain includes 
Jaluit, Kwajalein, Rongelap, Bikini, and Eniwetok. Both chains have 
numerous smaller atolls. An atoll normally consists of a perimeter of 
flat coral islands surrounded by reefs with a lagoon in the center. The 
lagoons are generally navigable since the coral reefs usually have 
breaks which permit seaborne traffic to enter and exit the atoll with 
comparative ease. There are 32 separate island groups in the Mar- 
shalls with 867 reefs, spread over 400,000 square miles of ocean. 
Kwajalein, the world's largest coral atoll, with over 90 islands, is lo- 
cated in the geographic center of the Marshalls and is approximately 
2,100 nautical miles southwest of Pearl Harbor. The islands generally 
are narrow and flat and only two to three miles in length. Even the 
larger islands rise only about twenty feet above sea level. Although 
some of the small islands are barren, most have heavy undergrowth, 
and the larger ones also have coconut palms, breadfruit trees, and 
scrub pines. On most islands road networks were primitive or nonex- 


165 ° E Rongelap 

C Bikini Atoll - Atol [ Rongerik 

Eniwetok Atoll 
Atoll Ailinginae Atoll 

Wotho Atoll ■?» 

Utirik Atoll 


■ Ailuk Atoll -y 


Kwajalein Atoll ^ 

Likiep Atoll 

C " Wotje Atoll 


Lib I 


Maloelap Atoll 

Namu Atoll '' : ; 
Ailinglapalap Atoll 

Namorik Atoll 

Kili I 
Ebon Atoll 


<s> - '.. 



^ Makin Atoll 

200 O Marakei Atoll 

Nautical Miles Abaiang Atoll 

Tarawa Atoll 

"S* Maiana Atoll 

• Apamama Atoll 
Kurial ' 0°- 

^ \ Nonouti Atoll 

-t, _ ... 'Atoll 
^ Tabiteuea 

<S* Atoll Tamana I 

175°E Arorae I 

istent in 1942, but one or more islands in each major group were 
large enough to accommodate an airstrip. Even prior to World War 
II the Japanese had constructed barracks, airfields, piers, and other 
military installations on many of the islands, and during 1942 and 
1943 they were hard at work fortifying them further. 

Faced with conducting operations across vast stretches of water 
on mostly unimproved islands, Admiral Nimitz developed an op- 
erational concept of seizing one island chain to support operations 
in the next chain. Before attacking the Marshall Islands, Nimitz's 
forces therefore had seized Tarawa and Makin in the Gilbert Is- 
lands, some 565 nautical miles south of the Marshalls, in November 
1943. The U.S. Army's 27th Infantry Division had secured Makin 
against only light Japanese resistance, but the U.S. 2d Marine Di- 


vision took strongly fortified and defended Tarawa only after suf- 
fering some of the heaviest American casualty rates of the war. 

The seizure of the Gilberts, especially the invasion of Tarawa, 
marked the first time an American force had assaulted a heavily 
fortified enemy beachhead from the sea, and despite sound am- 
phibious doctrine, problems were apparent. Instances of inade- 
quate air support due to poor communications and coordination, 
ineffective naval gunfire especially during the preinvasion bom- 
bardments, and inadequate quantities of equipment and materiel, 
as well as a shortage of amphibian tractors, all cost lives and de- 
manded immediate solutions for the rest of the campaign. How- 
ever, the landings, especially those at Tarawa, showed that the U.S. 
Navy and amphibious forces were capable of securing such isolated 
outposts with relative speed despite strong opposition. 

The U.S. victories at Tarawa and Makin achieved the mission of 
reducing the distance aircraft would have to travel to reach the 
Marshalls. U.S. warplanes could now conduct and carry out com- 
bat and photographic missions deep within enemy territory. With- 
out that advantage, the campaign against the Marshalls, Operation 
Flintlock, would have been much more difficult and costly. 


Just as debate surrounded American strategy for reconquest of 
the Pacific, so too did it affect the more specific plans to secure the 
Marshall Islands. The JCS War Plans Committee recommended seiz- 
ing Wotje and Maloelap at the northern edge of the Marshalls, with 
subsequent attacks on other major islands once initial operating and 
logistical bases had been established. Rear Adm. Richmond Kelly 
Turner, commander of the Fifth Amphibious Force, agreed with the 
Joint Chiefs' planners, as did Marine Corps Maj. Gen. Holland M. 
Smith, commander of the V Amphibious Corps, and Vice Adm. Ray- 
mond A. Spruance, the Fifth Fleet commander. Admiral Nimitz, 
however, disagreed and instead proposed making Kwajalein, in the 
center of the Marshalls, the primary objective. Simultaneous air at- 
tacks on Kwajalein, Wotje, and Maloelap would neutralize more than 
65 percent of the enemy aircraft facilities in the islands, but there 
would be only a single landing. Nimitz argued that a bold thrust at the 
heart of the Marshalls would both surprise the Japanese and allow 
the development of a base from which other occupied islands could 


be easily neutralized. Concentrating resources on a single decisive 
landing also would reflect the lessons of the Tarawa battle. 

In making his decision, Nimitz had the benefit of intelligence 
reports not available to his subordinates. In early 1943, Allied 
cryptographers had achieved a quantum breakthrough in cracking 
Japanese military codes. Code-named Ultra, the deciphered in- 
tercepts told Nimitz that the Japanese had shifted the bulk of their 
fighting forces to the outer Marshall Islands, anticipating an attack 
on the periphery. His decision to strike directly at Kwajalein was 
thus eminently sensible. He selected 17 January 1944 as the inva- 
sion date for Kwajalein, but because of supply and training diffi- 
culties he subsequently rescheduled the assault for 31 January. 

By early 1944, Nimitz's subordinates had more than sufficient 
sea, air, and ground forces available to carry out the conquest of the 
Marshall Islands. The U.S. Fifth Fleet, the main strike arm in the 
Central Pacific, in the fall of 1943 had 6 heavy, 5 light, and 8 escort 
aircraft carriers. Additionally, the fleet possessed 12 battleships, in- 
cluding 5 new ships, and 9 heavy and 5 light cruisers. Fifty-six de- 
stroyers rounded out the considerable combat power of the fleet. 

The principal landing force for the Kwajalein operation was 
the Fifth Fleet's Fifth Amphibious Force, commanded by Admiral 
Turner. Based on experience gained in earlier operations, Turner 
controlled the transport ships, cargo vessels, landing craft, and 
landing ship docks, but he also commanded the destroyers, escort 
carriers, cruisers, and battleships that would directly support the 
assault. Land-based naval aircraft were under the command of 
Rear Adm. John H. Hoover. 

General Smith, commander of the V Amphibious Corps, con- 
trolled the ground forces committed to the operation. These were 
the newly organized 4th Marine Division, then training in the 
United States; the independent 22d Marine Regiment from Samoa; 
the Army's 7th Infantry Division, which had participated in the 
seizure of Attu and Kiska in the Aleutian Islands; and the 2d Bat- 
talion, 106th Infantry, 27th Infantry Division. The rest of the 106th 
and the 1 1 1th Infantry were designated as a seaborne reserve. Maj. 
Gen. Harry Schmidt commanded the 4th Marine Division, while 
Maj. Gen. Charles H. Corlett commanded the 7th Infantry Divi- 
sion. The 22d Marines was commanded by Col. John T. Walker, and 
the 2d Battalion, 106th Infantry, by Lt. Col. Frederick B. Sheldon. 

While the Allies settled their plans, the Imperial Japanese Navy 
and Army high commands were reacting to the naval and land de- 


feats which had started with Guadalcanal and Midway in 1942. By 
September 1943 they had decided to shrink their defensive perime- 
ter around the Japanese home islands. With the Solomons and 
portions of New Guinea already lost, they designated the Gilbert 
and Marshall Islands as expendable outposts, but they decided to 
reinforce them strongly to make the price of conquest higher. In 
the last quarter of 1943 the Japanese thus dispatched additional 
ground forces to the Marshalls, distributing them among the outer 
islands, as Ultra revealed. 

Within the Marshalls, Kwajalein was the headquarters for the 
6th Base Force, which administered the islands and was com- 
manded by Rear Adm. Monzo Akiyama. His headquarters was, in 
turn, subordinate to the Japanese 4th Fleet, based at the fortified is- 
land of Truk. The commander of the 4th Fleet was Vice Adm. 
Masashi Kobayashi, who had received responsibility for Wake Is- 
land, Guam, the Gilbert Islands, Nauru, and Ocean Island in addi- 
tion to the Marshalls shortly after the attack on Pearl Harbor. 

Admiral Kobayashi commanded a fleet in name only. The old 
Japanese light cruisers Naka, Isuru, and Nagara and the 22d Air 
Flotilla were the only major combat forces he controlled. Isuzu 
and Nagara had both been damaged by U.S. naval air prior to the 
invasion of Kwajalein and had been withdrawn for repairs. Just be- 
fore Operation Flintlock commenced, 4th Fleet personnel in the 
Marshalls totaled 28,000 including Korean laborers who were 
building fortifications. 

In fact, the U.S. assault on the Marshalls had begun on 20 
November 1943. Because Mille Atoll in the eastern chain of the 
Marshalls was within Japanese fighter range of the Gilberts, Nimitz 
had attacked the atoll even before the U.S. Army and Marine forces 
stormed ashore at Makin and Tarawa. Although the Japanese lost 
seventy-one planes in the Marshalls that month, most were imme- 
diately replaced from Truk or the Japanese homelands. Taroa air- 
field on Maloelap became the target of American air attacks starting 
on 26 November, but it remained an operational field until 29 Jan- 
uary 1944. Airfields on Jaluit and Wotje were then lightly attacked in 
early January, as was the entire island of Kwajalein. 

As D-day for the Marshalls approached, attacks on Japanese 
airfields on the islands accelerated. The Japanese had 110 opera- 
tional planes in the Marshalls on 25 January, but Ultra intelli- 
gence reports pinpointed their location. In a single strike on 29 
January, Nimitz 's forces destroyed or damaged ninety-two enemy 


aircraft on Roi-Namur. By D-day, 1 February 1944, only fifteen 
Japanese planes in the Marshalls were operational. The attackers 
therefore now had absolute air superiority. 

Although the Japanese had expected an American fleet to appear 
somewhere in the Marshall Islands, they were surprised when one ar- 
rived off Kwajalein. Since Imperial Headquarters in Tokyo had rea- 
soned that the American forces would begin at the outer islands and 
work inward toward Kwajalein, the building of fortifications on that 
island had received little priority. In addition, the Japanese believed 
that any landing would come from the seaward side of an island, as 
opposed to the lagoon side, and they had oriented their defenses in 
that direction. Only after receiving intelligence reports from Tokyo 
concerning the capabilities of the American LVT (landing vehicle, 
tracked), which had demonstrated its ability to climb over coral reefs, 
were they now finally beginning to construct defensive positions on 
the lagoon side of many islands. But ultimately, little in-depth defense 
was possible because most of the islands were so narrow. 

Nimitz's plan for the capture of the Kwajalein Atoll was rela- 
tively straightforward. The 4th Marine Division was ordered to 
capture Roi-Namur and other islands in the northeast quadrant of 
the atoll, while the Army's 7th Infantry Division was to seize the is- 
land of Kwajalein itself (44 nautical miles south of Roi-Namur) in 
the extreme southeast end of the atoll. Additionally, Admiral Spru- 
ance received approval to seize Majuro on the eastern edge of the 
Marshalls in order to provide a fleet base and airfield for subse- 
quent operations. The 2d Battalion of the 106th Infantry was as- 
signed this mission. 

The island of Kwajalein is two and one-half miles long and 800 
yards wide for most of its length, tapering to 300 yards wide at its 
northern end. The seaward side had long been fortified, but since 
the enemy had also been erecting defenses on the lagoon side, 
General Corlett decided to avoid a frontal assault. His 7th Infan- 
try Division was to come ashore on the western end of the island, 
which had a beach 400 yards deep, and attack with two regiments 
abreast. On 31 January, the day before the assault, his forces were 
also scheduled to seize four small islands surrounding Kwajalein to 
serve as artillery bases and to ensure unimpeded access to the la- 
goon. General Schmidt's plan for capturing Roi-Namur was similar. 
His forces would seize five islands surrounding his main objective 
on 31 January and conduct their primary landing on 1 February. 



R01 l /m^, NAMUR 1 


Nautical Miles 

(Ennylabegan I) ~ 
(Enubuj I) 


Japanese defenders on Kwajalein and the nearby islands to- 
taled 5,000, with another 4,000 on Roi-Namur. Only about half 
were combat troops. Kwajalein had more than a hundred buildings 
and an airfield with a 5,000-foot runway with various taxiways and 
ramps capable of handling large numbers of fighters and bombers. 
The island also had docks and a long pier. 

Since large portions of Kwajalein were covered by thick vege- 
tation, a complete intelligence report on potential defenses was 
impossible. Aerial photography provided excellent views of 
beaches and open areas, but it could not penetrate the thick brush 
and palm trees to reveal what fortifications lay beneath. General 
Corlett had to rely on the belief of U.S. intelligence analysts that 
Japanese defenses on the island were substantial. 

The Americans were well prepared. The designated invasion 
forces had received specialized training in advanced amphibious 
techniques, marksmanship, and jungle warfare. Captured Japanese 
weapons had been fired during practice landings so that troops could 
recognize their sounds. Detailed intelligence briefings relating to 
weapons, fortifications, garrison strength, and the type of resistance 
expected on Kwajalein led commanders to prepare bangalore tor- 


February 1944 

Nautical Miles 


Cohen (Ennugenliggelap I) 

Clifton lEIIer 

Clifford (Legan !) 

Clement (Mann I) 
Clarence (Torrulj I)' 

Chauncey (Gehh I) 

Ashberry (Getlinam I) 

August (Omelek I) 

Barney " Augustine (Kwadack I) 

(Eniwetakl) /> „ ... ... d»m- 

fn\ Bascome (Meek I) M IN 

Bennett (Bigej I) 

.'■ Benson 


W Berlin (North Gugegwe) 
Beverly (South Gugegwe) 

Carlson (Enubuj 1} 

Blakenship (Lot 1} 

Burton (Ebeye I) 


pedoes, light explosives, and satchel charges containing twenty-five 
pounds of TNT for use against reported concrete and log bunkers. 
Both Army and Marine Corps leaders were determined that the 
costly problems of Tarawa would not be repeated in the Marshalls. 

Logistics had also received careful attention. The logistics plan 
called for the task force to carry 42 days of rations, 5 days of water, 10 


units of fire (a unit of fire equated to a weapon's expected expendi- 
ture of ammunition in a single day of combat) for antiaircraft guns 
and 105-mm. howitzers, 8 units of fire for other categories of ammu- 
nition, and 30 days of other supplies. Leaving nothing to chance, 
Special Service supplies included 50 harmonicas and 7 ukuleles. The 
invasion force seemed properly equipped for any eventuality. 

The 7th Infantry Division's Cavalry Reconnaissance Troop and 
Company B, 111th Infantry, opened the Army's operations in the 
Marshalls on 31 January. At 0330, using rubber assault boats to 
travel 800 yards from transports to the shore, they attacked and cap- 
tured the islands of Cecil and Carter and secured the Cecil Pass into 
the Kwajalein lagoon. They encountered only scattered resistance, 
killing twenty-one Japanese while suffering only one wounded. 

At daybreak units of the 7th Infantry Division's 17th Infantry 
assaulted two other small islands, Carlos and Carlson. Both were 
needed to provide artillery platforms for the coming attack. Resis- 
tance on both islands was nearly nonexistent, and the operations 
took less than three hours. At 1125 the 7th Division's artillery 
began landing four battalions of 105-mm. howitzers and one bat- 
talion of 155-mm. howitzers. The preinvasion bombardment of 
Kwajalein began that afternoon at 1500. 

Battleships and heavy cruisers joined the preinvasion bom- 
bardment at first light on 1 February, firing 7,000 rounds of 14-inch, 
8-inch, and 5-inch ammunition during the period leading up to the 
assault. Exploding shells and tall columns of black smoke blan- 
keted Kwajalein from end to end. The 7th Division artillery on 
Carlson fired 29,000 rounds at Kwajalein in support of the land- 
ings, and the Army Air Forces added six B-24 bombers from bases 
at Apamama to the effort, dropping fifteen 1,000- and 2,000-pound 
bombs on Kwajalein's fortified areas. In addition, for the first time 
combined Army-Navy underwater demolition teams were used to 
search the beaches for underwater obstacles and mines. In the case 
of Kwajalein, none were found. 

The collective power of the preinvasion bombardment by the 
Army, Navy, and Air Forces was literally overwhelming. The par- 
ticipants later described the naval gunfire as "devastating — the en- 
tire island looked as if it had been picked up 20,000 feet and then 
dropped — All beach defenses were completely destroyed, includ- 
ing medium and heavy anti-aircraft batteries." 

The 32d and 184th Regimental Combat Teams of the 7th In- 
fantry Division began landing at 0930 on 1 February. LVTs, LCIs 


The effects of preinvasion bombardment on Kwajalein. (National 

(landing craft, infantry), and DUKWs, new amphibious trucks, 
ferried troops and equipment ashore. Gunboats fired when landing 
craft neared the beach, but enemy mortars and automatic weapons 
still greeted the troops when they stormed ashore. However, the 
impact of the preinvasion bombardment was evident. Engineers 
had only one pillbox to destroy on the beach; the others were re- 
duced to ruins. Despite rubble from trees and fortifications, and 
craters from bombs and naval gunfire, the first four waves of the 
assault force were ashore by 0945. 

As the Americans moved inland, armored amphibian tractors 
with 37-mm. guns and flamethrowers provided support. By night- 
fall six infantry battalions supported by four medium tank compa- 
nies were ashore, having encountered little effective resistance. 
That evening Japanese troops executed scattered counterattacks, 
but American artillery kept any large formations from gathering 
momentum. Infiltration by small Japanese units caused some in- 
termittent combat for most of the night, though by midnight re- 


ports indicated that no more than 1,500 of the island's original de- 
fenders remained alive. 

On the next morning, 2 February, reserve battalions of the 32d 
and 184th Regimental Combat Teams prepared to pass through the 
units landed on D-day to continue the attack. The battleship Idaho, 
the cruiser Minneapolis, 4 destroyers, and 5 Army artillery battalions 
delivered preparatory fires, and 15 Navy dive bombers hit targets at 
0800 as the Americans moved out. Tank-infantry teams then at- 
tacked the remaining Japanese pockets of resistance. That night 
scattered groups of the enemy, however, continued to emerge to ha- 
rass rear areas, forcing units to defend themselves in all directions. 

By the morning of the third day there were approximately 300 
Japanese in the unconquered 1,000 yards of the island. Organized 
resistance ended shortly thereafter as the Americans finished their 
sweep of the island, although both regimental combat teams spent 
the remainder of 4 February mopping up. Each enemy bunker, 
trench, and building had to be checked and rechecked for Japanese 
soldiers who had evaded initial capture or death. The island had 
been secured at a minimal cost. U.S. forces suffered 177 killed and 
1,000 wounded on Kwajalein, but only 125 Korean laborers and 49 
Japanese survived as prisoners. Americans estimated that 50 to 75 
percent of the Japanese had been killed in the preparatory bom- 
bardments. Earlier intelligence reports that the island had sub- 
stantial defenses proved to be exaggerated. Most of the fortifica- 
tions clearly had been hastily constructed. 

As the fighting progressed from one end of Kwajalein to the 
other, the 7th Division quickly began to consolidate its prize. Sup- 
port and engineer troops landed and began to rebuild the island as 
an American base. Just days after the cessation of fighting Kwa- 
jalein's airfield was functioning, and American planes were attack- 
ing islands in the Marshalls still under Japanese control. Elsewhere 
division troops secured adjacent parts of the Kwajalein Atoll. 

Chauncey Island northwest of Kwajalein Island fell on 2 Febru- 
ary. Casualties were 14 Americans wounded and 125 Japanese 
killed, mostly from shelling. At 0930 on 3 February the 17th In- 
fantry assaulted Burton Island. Although so small (1,800 yards by 
250 yards) that the Americans could employ only four medium 
tanks abreast, Japanese resistance was fierce. Determined enemy 
soldiers fought from bunkers until killed by tanks or engineers 
using demolitions and flamethrowers. The one-and-a-half-day op- 


Flamethrower in use against a Japanese blockhouse. (National 

eration cost the Americans 7 killed and 82 wounded; the Japanese 
lost 450 killed, with 7 captured. 

While Burton was being subdued on 3 February, other ele- 
ments of the 7th Infantry Division seized the tiny coral outcrop- 
pings of Buster and Byron, located between Kwajalein and Burton, 
without opposition. On 4 February American forces landed on 
Burnet and Blakenship Islands, located to the north of Burton. 
On the former, forty natives cheerfully submitted to capture. On 
Blakenship a small number of marooned Japanese sailors and Ko- 
rean laborers had to be subdued with clubs and bayonets before 
the island could be declared secure. 

Over the next few days the remaining islands in the southern 
portion of Kwajalein Atoll were seized with only limited effort. 
Bennett Island was an exception. There, Japanese in pillboxes and 
dugouts fanatically resisted. Rather than expend American lives, 
tanks were brought ashore, and the enemy was soon subdued. 
American casualties were 1 killed and 2 wounded, while the enemy 


Marines attack a blockhouse on Roi-Namur. (National Archives) 

lost 94 killed. For the entire southern Kwajalein operation, Amer- 
ican casualties were 142 killed, 845 wounded, and 2 missing. The 
best estimate of enemy losses was 4,938 dead and 206 captured, of 
whom 127 were Korean laborers. 

Meanwhile, the marines were wrapping up their assigned missions 
in the sixty-two islands in the upper half of the atoll. On 3 1 January the 
4th Marine Division invaded five islands: Ivan, Jacob, Albert, Allen, 
and Abraham. These five flanked Roi-Namur, the main objective, 
and like Carlson in the south were to be artillery platforms. By the end 
of the day the islands were secure, and four battalions of artillery and 
a considerable number of mortars had been emplaced. Capturing the 
islands cost the lives of 18 marines, with 8 missing and 40 wounded, 
while estimates placed Japanese losses at 135 killed. 


On 1 February the 23d and 24th Marine Regiments began the 
assault against Roi-Namur. Roi, the objective of the 2d Battalion, 
23d Marines, was basically an airfield with little cover and few for- 
tifications, connected to Namur by a narrow causeway As a result 
of the preparatory bombardment, about 250 of the 400 Japanese 
on the eastern half of the island were killed. Despite choppy waters 
and inexperienced troops, the invasion was successful. Resistance 
was very light, and American losses totaled 3 killed and 11 
wounded during the one day it took to secure the island. 

The 24th Marines had tougher going. Namur's topography fa- 
vored its defenders. Not only were there numerous buildings and 
bunkers, but much of the island was covered by thick brush which 
had only been further tangled by the substantial preliminary bom- 
bardment. The early-model radios became water-soaked and inop- 
erative, thwarting effective communications between units, and the 
logistical supply of the troops ashore still experienced problems. The 
invading marines, following delays caused by inexperienced boat 
crews, landed on 1 February at 1133 against initially light Japanese re- 
sistance. The Americans had advanced about three to four hundred 
yards inland when a tremendous explosion occurred. The resultant 
concussion and the large falling fragments of concrete and metal 
killed twenty marines and wounded fifty others. A Marine demoli- 
tion party had unknowingly blown up a Japanese torpedo magazine. 
The explosion acted as a goad to the Japanese defenders who 
launched localized counterattacks. These events brought the marines' 
advance to a temporary halt, but they quickly recovered, pushed on, 
and by nightfall two-thirds of the island was in friendly hands. 

As on Kwajalein, the Japanese harassed the Americans on 
Namur throughout the night. When approximately 100 Japanese 
soldiers launched the one serious attack, most of them were killed in 
hand-to-hand fighting. At dawn the marines continued their assault, 
and by 1215 they had secured the island. Following mopping-up op- 
erations on the small islands near Roi-Namur, Kwajalein Atoll was 
declared secure. The 4th Marine Division suffered a total of 737 ca- 
sualties, including 190 killed, while estimated enemy losses totaled 
3,472 dead, with 40 Korean laborers and 51 Japanese captured. 

On the same day that the first landings were being made on 
Kwajalein Atoll, Admiral Spruance also initiated Operation Sun- 
dance, an assault against Majuro Atoll to secure additional air 
and sea bases. Approximately 265 nautical miles southeast of Kwa- 
jalein, Majuro possessed the largest potential fleet anchorage in the 


Central Pacific. The Army's 2d Battalion, 106th Infantry, 27th In- 
fantry Division, and the Marine V Amphibious Corps' Reconnais- 
sance Company were charged with the mission. The marines were 
to land, locate that Japanese troops, and eliminate them. The 106th 
Infantry was to provide reinforcements if required. About 400 
Japanese were reportedly defending the area. 

Sundance proved almost a nonevent. When some marines 
went ashore on the outlying islands of Dalap and Darrit, they 
found an English-speaking native, Michael Madison, who related 
that the Japanese garrison had left Majuro almost a year earlier. 
Madison's information proved accurate. On Majuro the marines 
found a lone Japanese warrant officer who had been left as a care- 
taker. With his capture, the island was declared secure. 

The seizure of Kwajalein, Roi-Namur, and Majuro with com- 
paratively light casualties permitted Admiral Spruance to acceler- 
ate the pace of operations in the Marshalls. Some 10,000 troops of 
the 22d Marines and the two battalions of the Army's 106th In- 
fantry that had been held back as a reserve for the Kwajalein Atoll 
operation had not even been committed to battle. Spruance there- 
fore moved up the invasion of Eniwetok Atoll, code-named Oper- 
ation Catchpole, from 1 May to 17 February. The Eniwetok Atoll 
includes Eniwetok Island and a number of other islands including 
Parry and Engebi. Covering 383 square miles, it is the second 
largest atoll in the Marshalls. Since plans called for it to become a 
major fleet base for upcoming operations in the Central Pacific, 
Spruance regarded its seizure as critical to the success of his Pacific 
strategy. Although he initially believed that there were only 700 de- 
fenders scattered through the atoll, Ultra intelligence soon con- 
vinced him that the garrison had been reinforced. 

The Japanese had not fortified Eniwetok Atoll until 1944. But 
as the scope and direction of the American Central Pacific strategy 
became apparent, they greatly strengthened the atoll's defense 
with the 1st Amphibious Brigade about six weeks prior to the U.S. 
invasion. Its commander, Maj. Gen. Yoshimi Nishida, attempted to 
construct a uniform defensive system throughout the atoll. How- 
ever, his efforts were slowed by frequent American air attacks 
which damaged freshly built defensive positions, allowed Japanese 
soldiers and sailors little time to rest, and restricted incoming sup- 
plies. The fortifications that the defenders finally managed to erect 
consisted generally of central defensive positions with "spider" 
holes radiating out from them. Dense foliage on the island con- 



Zinnia (Bogon 1} 

11°30'N - 

Lilac (Jeroru I) f iadyslipper 
(Japtan I) 

Nautical Miles 



cealed their extent from U.S. aerial reconnaissance. Yet once again 
the size of the atoll made a defense in depth impossible, and 
Nishida and his officers knew that their survival depended on de- 
stroying assault troops as close to the beach as possible. 

The preliminary phase of the Eniwetok Atoll invasion began 
on 17 February 1944. To isolate the target area, Spruance launched 
two massive carrier strikes against the Japanese island fortress of 
Truk, some 700 miles to the west, on 17-18 February. The air at- 
tacks destroyed several hundred aircraft, the bulk of the Japanese 
air power in the region, as well as twenty transport ships and sev- 
eral combat and auxiliary vessels, making any assistance to the 
Eniwetok defenders virtually impossible. Meanwhile the preinva- 
sion naval bombardment of the atoll had begun at 0659 on 17 
February. Simultaneously Canna and Camellia, two nearby islands, 
were occupied and immediately converted for use as artillery plat- 


Landing craft pass supporting warships during the invasion of 
Eniwetok. (National Archives) 

forms to harass the next target, Engebi Island, northwest of Eni- 
wetok, with sporadic fire around the clock. On that same day, un- 
derwater demolition teams checked the beaches off Engebi but 
discovered no underwater obstacles. 

Phase II of the operation began promptly on the morning of 18 
February when the 22d Marines landed on Engebi, with the 
Army's 106th Regiment acting as shipboard reserve. Two battal- 
ions of marines, supported by tanks and a cannon company from 
the 106th Infantry, landed at 0844 and quickly moved inland 100 
yards. Opposition was light, and any resistance was immediately 
bypassed. By 0925 naval gunfire was halted, and in six hours the 
marines had secured the island. Casualties were 85 killed or miss- 
ing and 521 wounded, compared to Japanese losses of 1,276 killed 
and 16 captured. 

From prisoners and documents captured on Engebi, U.S. intelli- 
gence learned that Eniwetok Island proper was defended by only 
about 550 enemy soldiers and some 200-300 administrative and sup- 
port personnel. Based on this information, Rear Adm. Harry W. Hill, 
the Eniwetok task group commander, directed the 1st and 3d Battal- 


ions of the 106th Infantry, supported by Marine Corps tanks, to land 
simultaneously after a relatively light preparatory bombardment. 

The naval bombardment began promptly at 0719, 19 February, but 
its brevity proved a mistake. Few of the Japanese defensive works 
were destroyed, and the first wave of the assaulting force experienced 
difficulties from the start. As the LVTs hit the beaches, they were 
blocked from moving inland by the terrain and heavy automatic 
weapons fire. Once the 106th 's forward momentum was stopped, the 
Japanese quickly counterattacked, supported by accurate mortar fire 
and led by enthusiastic Japanese officers. The assaults were repulsed 
after a number of fierce hand-to-hand engagements. 

In view of the strength and determination of the enemy resis- 
tance, Admiral Hill ordered the 3d Battalion, 22d Marines, ashore. 
But even with these additional forces committed to battle, fighting 
continued until 21 February, D plus 4, when the island was finally 
secured. Total American casualties, predominantly Army, were 37 
killed and 94 wounded; Japanese losses were in excess of 800. 

The final phase of the Eniwetok operation was the seizure of 
Parry Island by the 22d Marines. The amphibious assault, originally 
scheduled for 17 February, was delayed for three days as a result of 
the difficulties encountered in seizing Eniwetok Island. But the 
delay allowed Hill to orchestrate a much more extensive preparatory 
bombardment. While the Army's 104th Field Artillery Battalion 
took Parry under fire from Eniwetok Island, the battleships Ten- 
nessee and Pennsylvania and the heavy cruisers Indianapolis and 
Louisville pounded it from the sea. Naval gunfire totaled 944.4 tons 
of shells in three days. The 104th Artillery added 245 tons to the 
bombardment, and air-delivered bombs raised the total by another 
99 tons of munitions. In contrast, only 204 tons of ordnance had 
been expended earlier on Kwajalein. American commanders were 
determined that casualties would not result from a lack of adequate 
preinvasion bombardment. 

At 0900 on 22 February the 22d Marines stormed ashore. Resis- 
tance was similar to that encountered on Engebi. There were no 
major counterattacks, and small groups of the enemy were identified 
and quickly eliminated. Three Japanese light tanks engaged the 
marines on the beaches, but they were quickly destroyed without 
American losses. Nevertheless Japanese resistance seemed to stiffen 
after their tank attack, and the marines requested naval gunfire. 
The first salvo fell short and caused extensive friendly casualties, but 
the rest struck the enemy formations and broke the back of the de- 


fenders. Parry was declared secure by the commander of the 22d 
Marines at 1930. Total American casualties in the battle for Eniwe- 
tok Atoll were 262 killed, 757 wounded, and 77 missing. Japanese 
losses amounted to more than 2,000 dead. 

Following Parry's seizure, the marines secured the remaining, 
more lightly defended islands in the Marshalls. Code-named Flint- 
lock Jr., these missions were completed with relatively few casu- 
alties against only light resistance. Elsewhere, the islands of Wotje, 
Mille, Maloelap, and Jaluit, heavily defended by the Japanese, 
were effectively isolated, and their occupants were left to starve or 
to be bombed into submission until the war ended. The Eastern 
Mandates Campaign formally ended on 14 June 1944, although 
ships and planes would operate from bases in the Marshall Islands 
long after the war was over. 


The conquest of the Marshall Islands demonstrated the sound- 
ness of American amphibious doctrine, albeit on a small scale. As 
with earlier operations, American planners acquired much experi- 
ence in the campaign and applied new techniques which would be 
shaped and refined for subsequent operations. Two of the most im- 
portant lessons involved dose air support and naval gunfire. Before 
1944 continuous support from those services was more the exception 
than the rule. With the destruction of Japanese naval and air forces as 
the war progressed, and given American industry's tremendous out- 
put in ships and planes, the possibility of greatly increasing air and 
naval preinvasion fire support became both feasible and desirable. 

Another tactical advance was the introduction of specially 
equipped headquarters ships. Although such vessels had already 
appeared in the Mediterranean, they were first used in the Pacific 
during the Marshall Islands landings. Although no more than 
transport or supply vessels equipped with special command and 
communications facilities, they allowed commanders, both afloat 
and ashore, to direct multiple amphibious operations independent 
of the primary fleet command ship. In the Kwajalein operation, the 
USS Rocky Mount aptly demonstrated the value of this innovation 
by easily handling the communications for five separate commands 
engaged in the landings. 

The LVT, or Alligator, performed with the same versatility as it 
had at Tarawa. Lightly armored but heavily armed, these tracked 


"Radio Communications" by Edward A. Sallenback. (Army Art 

amphibians brought squads of men from ship to beach and then 
moved them inland when enemy fire was light. When the troops 
debarked, the LVTs returned to the ships to pick up additional re- 
inforcements. They could also act as supply vehicles and ambu- 
lances or in a dozen other useful roles. The DUKW, half boat and 
half truck, complemented the LVT Quickly dubbed the "Duck" by 
American foot soldiers, it greatly assisted in the buildup of supplies 
and materiel on the beaches. 

As the American forces perfected their tactics and their landing 
craft and equipment, the Japanese changed the nature of their de- 
fensive operations as well. Unfortunately for them, the results were 
often disappointing. In the Marshall Islands the defenders relied 
on thin beachline defenses with troops designated for immediate 
counterattack. This type of defensive arrangement was totally in- 
adequate. The weight of the American war machine was too heavy, 
and the firepower brought to bear on the beachheads was too 
great. The Japanese were nevertheless capable of making radical 


adjustments in their defensive postures. Saipan and Iwo Jima, con- 
siderably larger than the Marshall Islands, would be difficult and 
costly to take as a result. 

The relatively easy seizure of the Marshalls and the effective 
neutralizing raids on the Japanese fortress of Truk proved the 
soundness of Nimitz's decision to use the Central Pacific as the best 
route to Japan. By neutralizing and bypassing Truk, Nimitz saved 
many lives with no loss of tactical advantage. The Marshalls pro- 
vided the same facilities as Truk for both fleet anchorages and air- 
fields for future operations. In addition, the units designated for a 
possible landing on Truk — two Marine divisions and one Army di- 
vision plus assorted independent regiments — were able instead to 
begin training for the seizure of the Marianas, where plans called 
for Saipan and Tinian Islands to become long-range bomber bases 
for a massive aerial campaign against the Japanese home islands. 

The quick seizure of the Marshall Islands allowed Admiral 
Nimitz to advance the date for the invasion of the Marianas by 
twelve to thirteen weeks. At the same time, Japanese preparation 
time for the defense of islands like Saipan and Tinian was short- 
ened, and many of the U.S. units that had participated in the Mar- 
shalls operation, still relatively intact, were available for the Mar- 
ianas invasion. The overall importance of the rapid seizure of the 
Eastern Mandates thus cannot be overestimated. The Marshalls 
were not only a proving ground for new tactics and innovations but 
also a critical step in a chain of events that would lead to the 
Japanese surrender at Tokyo Bay. 



Further Readings 

A number of official histories provide carefully documented ac- 
counts of the Marshalls operations. They include Philip A. Crowl 
and Edmund G. Love, Seizure of the Gilberts and Marshalls (1955), 
a volume in the series United States Army in World War II; S. L. A. 
Marshall, Island Victory (1945); and Robert D. Heinl, Jr., and John 
A. Crown, The Marshalls: Increasing the Tempo (1954). Naval ac- 
tions and support for the Marshalls operation can be found in 
Samuel Eliot Morison, History of United States Naval Operations in 
World War II, volume 7 , Aleutians, Gilberts, and Marshalls (1951). 
Marine operations are described in Henry I. Shaw, Jr., Bernard C. 
Nalty, and Edwin T. Turnbladh, History of the U.S. Marine Corps 
Operations in World War II, volume 3, Central Pacific Drive. Ed- 
ward J. Drea's work, MacArthur's ULTRA: Codebreaking and the 
War Against Japan, 1942-1945 (1992), contains an excellent account 
of Allied cryptology operations in the Pacific. 

CMH Pub 72-23 

Cover: Landing on Carlson Island. (National Archives) 

PIN : 071800-000